CN111856735A - Objective lens for 40 times biological observation - Google Patents

Abstract

The invention discloses an objective lens for 40 times biological observation, which consists of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a diaphragm, an eighth lens and a ninth lens which are sequentially arranged from an object side to an image side, wherein the combined focal length of the first lens and the second lens is 10-15 mm, the third lens and the fourth lens form a first adhesive part, the focal length is 25-40 mm, the fifth lens, the sixth lens and the seventh lens form a second adhesive part, the focal length is 80-120 mm, the eighth lens and the ninth lens are a positive lens group and a negative lens group, the focal length of-0.5 < FG8/FG9< -5 is satisfied, wherein FG8 is the focal length of the eighth lens, FG9 is the focal length of the ninth lens, the total length from the first surface of the first lens to the second surface of the ninth lens is less than or equal to 58mm, and the total focal length of a lens formed by the nine lenses is 5mm or 4.5mm, the advantages are that the numerical aperture is increased to 0.75, the working distance is about 1.5mm, the effects of high resolution and long working distance are achieved, and the observation effect of the biological smear can be improved.

Description

Objective lens for 40 times biological observation

Technical Field

The invention relates to an objective lens, in particular to a 40-time objective lens for biological observation.

Background

With the development of the times, the medical consciousness of people is enhanced, the requirements of inspection and test are more and more, and the efficiency is relatively low when a hospital laboratory relies on an experienced doctor to make and read the film. The automatic slice scanner uses CCD as medium to collect image, and cooperates with the machine to automatically slice and sweep slice, and only one device is needed to complete the slice production and reading. The introduction of such a device greatly improves the efficiency of image acquisition and increases the throughput of hospital laboratories. The microscope then becomes an image acquisition tool and the human eye observation is replaced by the imaging element, which also introduces certain problems. Firstly, experiments show that the sensitivity of the CCD to an imaging image surface is far higher than that of the human eye, smear made by a machine automatic smear device is mostly a cover glass-free sample, only 1 medium of air exists between an observed object and an objective lens, the design of the conventional biological objective lens comprises 0.17 cover glass, the design of the objective lens is not matched with the actual condition, the aberration caused by the condition is not sensitive when the human eye observes, but the CCD cannot do; secondly, when a 40-time objective lens is used for observation at present, the distance between an observed object and the objective lens is shorter than 1mm, a doctor can move the platform up and down to avoid contacting with the objective lens when operating, but when the machine is used, the too short working distance causes great limitation to equipment for slicing up and down; thirdly, when observing fluorescent substances, in order to increase the scanning speed of the slice, a larger energy needs to be supplied to the camera, which requires a larger numerical aperture, and the numerical aperture of the existing objective lens for biological observation of 40 times is mainly 0.65. With increasing numerical aperture, both the field width and the working distance are correspondingly smaller. The invention has the following patent: the objective lens disclosed in CN201180031598.5 has a larger numerical aperture, but consists of 10 lenses and a diffractive optical element.

Disclosure of Invention

The invention aims to solve the technical problem of providing a 40-time objective lens for biological observation, which has no poor coverage, long working distance and large numerical aperture and can improve the biological smear observation effect.

The technical scheme adopted by the invention for solving the technical problems is as follows: a40 times objective lens for biological observation comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a diaphragm, an eighth lens and a ninth lens which are arranged in sequence from an object side to an image side, wherein the combined focal length of the first lens and the second lens is 10-15 mm, the third lens and the fourth lens form a first adhesive part with a focal length of 25-40 mm, the fifth lens, the sixth lens and the seventh lens form a second adhesive part with a focal length of 80-120 mm, the eighth lens and the ninth lens are a positive and negative lens group, and the focal length of-0.5 < FG8/FG9< -5 > is satisfied, wherein FG8 is the focal length of the eighth lens, FG9 is the focal length of the ninth lens, and the total length from the first surface of the first lens to the second surface of the ninth lens is less than or equal to 58mm, the overall focal length of a lens consisting of nine lenses is 5mm or 4.5 mm.

The first lens faces the object space and is a concave spherical surface, and faces the image space and is a convex spherical surface.

The second lens faces the object space and is a concave spherical surface or a plane, and faces the image space and is a convex spherical surface.

The third lens faces to the object plane, and the third lens faces to the image plane and is a concave spherical surface; the fourth lens is a convex spherical surface facing the object space and a convex spherical surface facing the image space, and the concave spherical surface facing the image space of the third lens and the convex spherical surface facing the object space of the fourth lens are glued together.

The fifth lens is a convex spherical surface facing the object space, the concave spherical surface facing the image space, the sixth lens is a convex spherical surface facing the object space, the convex spherical surface facing the image space, the seventh lens is a concave spherical surface facing the object space, and the convex spherical surface facing the image space.

The eighth lens is a plane or a convex spherical surface facing the object space and a convex spherical surface facing the image space.

The ninth lens is a concave spherical surface facing the object space and a concave spherical surface facing the image space.

Compared with the prior art, the invention has the advantages that aiming at the common medical objective lens with the magnification of 40 times and the image space field number of more than or equal to 25mm, the objective lens is formed by adopting the lens structure with specific parameters, and compared with the conventional objective lens, the numerical aperture of 0.65 is increased to 0.75 when the conventional objective lens is configured in the object space field range of 0.625mm, the numerical aperture is larger, the energy on the surface of the collected object is stronger, the working distance is about 1.5mm, the effects of high resolution and long working distance are achieved, and the observation effect of the biological smear can be improved; the design of 0.17 of coverage difference is removed, so that the size of the Airy spots on the image surface is smaller and the energy is more concentrated when the medical smear is observed; the invention only uses 9 lenses, has lower cost than the prior art, and is easier to reduce the processing cost when the lenses are all spherical rotational symmetry surfaces.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a field curvature diagram of an embodiment of the present invention, wherein the ordinate represents the angle of incident light, which may correspond to the number of fields of view of the objective lens, and the abscissa represents the magnitude of field curvature, and the three curves are field curvature curves of F light (486.1nm), d light (587.5nm) and C light (656.3nm), respectively;

FIG. 3 is a distortion diagram of an embodiment of the present invention, wherein the ordinate represents the angle of incident light, which may correspond to the number of fields of view of the objective lens, and the abscissa represents the magnitude of distortion;

FIG. 4 is a color focus shift plot of an embodiment of the present invention with the ordinate indicating the wavelength of light in um, the wavelength ranging from 0.486um to 0.6563um, and the abscissa indicating the range of focus shift;

fig. 5 is a schematic diagram of transmittance of an objective lens according to an embodiment of the present invention simulated by a computer, where the ordinate is transmittance of light in units, the abscissa is wavelength of light wave in units of nm, and the reflectance of light on each surface is set to 0%, i.e., the influence of a coating film on the optical design is eliminated.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

Example (b):

as shown in FIG. 1, a high power objective lens for improving the observation effect of a biological smear, which comprises a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a diaphragm G, an eighth lens L8 and a ninth lens L9 arranged in sequence from the object side to the image side, wherein the first lens L1 is a concave spherical surface facing the object side and a convex spherical surface facing the image side, the second lens L2 is a concave spherical surface or a plane facing the object side and a convex spherical surface facing the image side, the combined focal length of the first lens L1 and the second lens L2 is 10-15 mm, the third lens L3 is a plane facing the object side and a concave spherical surface facing the image side, the fourth lens L4 is a convex spherical surface facing the object side and a convex spherical surface facing the image side, the concave spherical surface 6866 of the third lens L8 is combined with the concave spherical surface of the fourth lens L4 facing the object side, and the fourth lens L3527 is combined with the fourth lens L4, a focal length of 25-40 mm, a convex spherical surface facing an object of the fifth lens L5, a concave spherical surface facing an image, a convex spherical surface facing an object of the sixth lens L6, a convex spherical surface facing an image, a concave spherical surface facing an object of the seventh lens L7, a convex spherical surface facing an image, a concave spherical surface facing an image of the fifth lens L5, a convex spherical surface facing an object of the sixth lens L6, a convex spherical surface facing an image of the sixth lens L6, a concave spherical surface facing an object of the seventh lens L7, a concave spherical surface facing an image of the fifth lens L5, the sixth lens L6 and the seventh lens L7, a second cemented element GL2 having a focal length of 80-120 mm, a flat or convex spherical surface facing an object of the eighth lens L8, a convex spherical surface facing an image, a concave spherical surface facing an object of the ninth lens L9, a concave spherical surface facing an image, a ninth lens L8 and a ninth lens L9, satisfy FG 5-8/3 < FG < 3.3 >, wherein FG8 is the focal length of the eighth lens L8, FG9 is the focal length of the ninth lens L9, the total length of the first lens object side to the ninth lens power side is 58mm or less, and the total focal length of the lens made up of the nine lenses is 5mm or 4.5 mm.

The following is one example, but not all examples, of embodiments of the invention.

Description of the drawings: the lens is arranged from the image space to the object space in sequence, and the distance from the D surface of the last spherical surface 15 line, namely the R surface of the last lens, to the observed object.

	R	D	ND	VD
					Spherical surface 1	-7.51	1	1.49	70.4
Spherical surface 2	50.42	4.05
					Spherical surface 3	18.1	2.2	1.74	32.3
Spherical surface 4	-324.98	16.3
					Spherical surface 5	41.05	1.2	1.61	44.2
Spherical surface 6	9.04	6.5	1.50	81.6
					Spherical surface 7	-9.1	1.2	1.74	32.3
Spherical surface 8	-20.96	0.1
					Spherical surface 9	9.65	6	1.46	90.3
Spherical surface 10	-14.61	1.1	1.74	32.3
					Spherical surface 11	∞	0.12
Spherical surface 12	9.06	2.9	1.50	81.6
					Spherical surface 13	92.63	0.14
Spherical surface 14	4.04	3.32	1.74	32.3
					Spherical surface 15	2.75	2.27

R represents a radius, D represents a thickness, ND represents a refractive index, and VD represents an Abbe number.

In this example, the combined focal length of the first lens L1 and the second lens L2 is 12.07mm, the focal length of the first glue GL1 composed of the third lens L3 and the fourth lens L4 is 31.43mm, the focal length of the second glue GL2 composed of the fifth lens L5, the sixth lens L6 and the seventh lens L7 is 104mm, the ratio of the focal length FG8 of the eighth lens L8 to the focal length FG9 of the ninth lens L9 is-1.74, the total length of the first lens object aspect to the ninth lens image aspect is 48.4mm, and the total focal length of the lens composed of the nine lenses is 5 mm.

As can be seen from the field curvature diagram of fig. 2 and the distortion diagram of fig. 3, the field curvature and distortion in the present invention are well corrected;

it can be seen from the color focus shift diagram of fig. 4 that the chromatic aberration along the axis of the lens is well corrected;

From the transmittance chart of the objective lens of fig. 5, it can be seen that the transmittance at 360nm is maintained at about 80%, and the use condition of most of fluorescence is satisfied.

Claims (7)

1. An objective lens for 40 times biological observation is characterized by comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a diaphragm, an eighth lens and a ninth lens which are arranged in sequence from an object side to an image side, wherein the combined focal length of the first lens and the second lens is 10-15 mm, the third lens and the fourth lens form a first adhesive member with a focal length of 25-40 mm, the fifth lens, the sixth lens and the seventh lens form a second adhesive member with a focal length of 80-120 mm, the eighth lens and the ninth lens are a positive and negative lens group, and the focal length of-5 < FG8/FG9< -0.5 > is satisfied, wherein 8 is the focal length of the eighth lens, FG9 is the focal length of the ninth lens, and the total length from the first surface to the second surface of the ninth lens is less than or equal to 58mm, the overall focal length of a lens consisting of nine lenses is 5mm or 4.5 mm.

2. The objective lens for 40 times biological observation according to claim 1, wherein the first lens is a concave spherical surface facing the object side and a convex spherical surface facing the image side.

3. The objective lens for 40 times biological observation according to claim 1, wherein the second lens is a concave spherical surface or a flat surface facing the object side and a convex spherical surface facing the image side.

4. The objective lens for 40 × biological observation according to claim 1, wherein said third lens faces the object plane and the image plane is a concave spherical surface; the fourth lens is a convex spherical surface facing the object space and a convex spherical surface facing the image space, and the concave spherical surface facing the image space of the third lens and the convex spherical surface facing the object space of the fourth lens are glued together.

5. The objective lens for 40 times biological observation according to claim 1, wherein the fifth lens element is a convex spherical surface facing the object side and a concave spherical surface facing the image side, the sixth lens element is a convex spherical surface facing the object side and a convex spherical surface facing the image side, and the seventh lens element is a concave spherical surface facing the object side and a convex spherical surface facing the image side.

6. The objective lens for 40 times biological observation according to claim 1, wherein the eighth lens element is a plane or a convex spherical surface facing the object side and a convex spherical surface facing the image side.

7. The objective lens for 40 times biological observation according to claim 1, wherein the ninth lens is a concave spherical surface facing the object side and a concave spherical surface facing the image side.

Images